The overarching goal of the proposed research is to learn how to optimize psychotherapy for those Veterans most in need and most likely to benefit from psychotherapy, older Veterans with chronic musculoskeletal pain. Chronic pain is a critical healthcare challenge, as the condition affects 50% of all Veterans and affects older Veterans most commonly, severely, and persistently. For years, chronic pain treatment has been notoriously difficult at VA and elsewhere, especially in light of the recent ?opioid crisis,? in which opioid analgesics, previously a mainstay of chronic pain treatment, have come under increased scrutiny. In response, CDC, VA/DoD, and some experts have called for enhancing and expanding psychosocial treatment options for chronic pain, such as psychotherapy, which are low risk for older Veterans who frequently have multiple medical comorbidities and are taking multiple medications. Yet standard VA psychotherapy approaches, such as Cognitive Behavior Therapy (CBT), have shown modest benefits for Veterans on pain and other related patient-centered outcomes (PCO), such as mood, anxiety, and sleep. In contrast, a novel psychotherapy approach, Emotional Awareness and Expression Therapy (EAET), has shown medium to large benefits for some chronic pain patients. Whereas CBT improves pain and negative emotion by teaching patients cognitive and behavioral coping skills, affecting brain regions that enhance ?cognitive control? of pain, EAET operates primarily through emotion regulation, which is thought to influence brain regions and circuits that modulate both physical pain and emotion?a mechanism absent from existing approaches. The literature and our pilot data indicate that patients who express a significant amount of emotional distress at baseline, such as high anxiety and depressive symptoms, may be particularly likely to benefit from EAET?s emotion regulation approach, whereas patients who express less emotional distress may derive more benefit from an approach like CBT, which does not require ready access to emotions. The proposed randomized clinical trial tests the hypothesis that EAET is superior to CBT on reduction in mean pain severity and other PCO (derived from IMMPACT recommendations). To examine which patients are most likely to benefit, this research also tests whether greater baseline emotional distress (using measures of anxiety and depression) predicts stronger benefits from EAET and whether lower baseline emotional distress predicts stronger benefits from CBT. Finally, this research explores whether the benefits of EAET are mediated by improved emotion regulation (using measures of ambivalence over emotional expression and emotional approach coping), the benefits of CBT are mediated by improved cognitive and behavioral coping (using measures of pain catastrophizing and adaptive coping), and whether the benefits of both are mediated by a stronger working alliance. We plan to enroll 160 multi-ethnic/multi- racial older Veterans (age 60-95 years) with chronic musculoskeletal pain at the West Los Angeles VA Medical Center, an ideal environment as the largest VA Medical Center on the West Coast. This research can introduce an additional, potentially more effective format of psychotherapy at VA so that more Veterans with chronic pain can respond. In addition, this research can lead to better treatment targeting and enhance our understanding of how psychotherapy treatments work. Finally, this research can facilitate the development of critical skills for the PI in psychotherapy research and pain management and enhance his ability to effect positive change for older Veterans.